Three decades of psychobiological research with rodents, nonhuman primates, and humans have documented the existence of individual differences in temperament, emotionality, behavioral and physiological reactivity, and personality, which we refer to as biobehavioral organization. These characteristics influence an individual's style of adaptation to its environment, and evidence shows that the quality of the animal's adaptations is associated with indices of psychological and physical health. At the California National Primate Research Center, we have developed a program to assess biobehavioral organization in infant rhesus monkeys. Our protocol includes a) collecting behavioral data in several situations designed to assess memory, responsiveness to mild challenges, and willingness to interact with novel objects; b) genotyping for polymorphisms in the promoter regions of two neuropsychiatric genes, the serotonin transporter and monoamine oxidase-A; c) assessing regulation of the hypothalamic-pituitary-adrenal system; and d) measuring routine hematologic parameters. Data from this resource are available to all CNPRC service and scientific staff via a web interface, to use for scientific and colony management purposes. In the current application, we propose the following specific aims: to continue performing our BioBehavioral Assessment on approximately 300 infant rhesus monkeys per year and to make these data available to qualified scientific and management staff through our web page as soon as the processing of the data is complete each year; to continue our ongoing efforts to identify the attributes of former participants in our BBA program that are at risk for poor adaptation to a captive environment as indexed by measures of chronic illness, abnormal behaviors, poor reproduction, and aberrant social function; to use existing statistical methods on our BBA data to establish individual profiles associated with poor outcomes as aids to colony management personnel to prevent health, behavioral, reproductive, and social problems; to continue to develop standardized tests that are shorter, simpler, and easier to administer than our current procedure, yet meet the same standards of reliability and predictive validity for our outcome measures.